Valve-gear



(No Model.) 3 Sheds-Sheet 2..

F. PILK'INGTON.

VALVE GEAR.

No 578,656. Patented Mar. 9,1897.

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(No Model.) Q I 3 SheetsSheet 3. F. PILKINGTON.

VALVE GEAR.

N0. 578,656. Patented Mar. 9, 1897.

ATTORNEYS.

UNITED STATES PATENT OFFICE.

FRANKLIN PILKINGTON, OF ANNISTON, ALABAMA.

VALVE-G EAR.

SPECIFICATION forming part of Letters Patent No. 578,656, dated March 9, 1897.

Application filed June 9, 1896. Serial No. 594,840. (No model.)

To aZZ whom it may concern:

Be it known that I, FRANKLIN PILKINGTON, of Anniston, in the county of Calhoun and State of Alabama, have invented a new and Improved Valve-Gear, of which the following is a full, clear, and exact description.

The object of the invention is to provide a new and improved valve-gear which is simple and durable in construction, not liable to get out of order, and arranged to produce, according to the speed of the engine, a variable automatic cut-off and a constant closing and opening of the exhaust at the proper time to produce highly economical results with but a single valve.

The invention consists principally of a lever connected with the valve-stem and controlled jointly by the shaft-eccentric and the governor-eccentric.

The invention also consists of certain parts and details and combinations of the same, as will be fully described hereinafter and then pointed out in the claims.

Reference is to be had to the accompanying drawings, forminga part of this specification, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is a plan view of the improvement. Fig. 2 is a side elevation of the same. Fig. 3 is a sectional side elevation of the same on the line 3 3 of Fig. 1. Fig. 4 is a reduced plan view of the yoke. Fig. 5 is a side elevation of the same. Fig. 6 is a reduced plan viewof the fulcrum-arm. Fig. 7 is a side elevation of the same. Fig. Sis a plan view of the rockerarm. Fig. 9 is a plan View of the lever, and Fig. 10is a diagrammatic view of the improvement as applied.

The improved valve-gear, as illustrated in Fig. 1, is used on a single slide-valve A, controlled jointly from the shaft-eccentric B, secured on a main driving-shaft O, and the governor-eccentric D of a shaft-governor of any approved construction, the said governor-eccentric being arranged to move transversely of the main shaft 0, as is well understood.

The eccentric-rod D of the governor-eccentric D is pivotally connected with a crank-pin E, held on the free end of the rocker-arm F, secured on a shaft F, mounted to turn in suitable bearings held on a frame G, forming part of the engine-frame and located between the steam-chest and the main shaft 0, as indicated in Fig. 10.

The crank-pin E is extended beyond the sides of the eccentric-rod D and the rockerarm F to form trunnions for a yoke H, extending transversely and provided with a longitudinally-extending side arm H, on which is secured a pin H engaged by the free end of the eccentric-rod B for the shafteccentric B.

The pin 11 is located a suitable distance below the crank-pin E, as plainly shown in Figs. 2 and 5. On the free end of the arm H is held a crankpin H connected by a link I with a pin J, held in one end of a lever J, fulcrumed on a transverse pin K, projecting laterally from an arm L, having its fulcrum on a pin H projecting from the forward end of the side arm H.

The pins H H and H are in alinement with each other, as plainly indicated in Fig. 5. The lever J is preferably provided with removable bearings J engaging the said pin K. The forward forked end J of the lever J carries a crank-pin J engaged by the head of a link N, connected with the valve-stem A of the slide-valve A. (See Figs. 3 and 9.)

The arm L is also engaged by a pin 0, proj ecting laterally from a rocker-arm P, turning on ashaft Q, secured on a suitable bracket G, attached to the frame G.

The operation is as follows: The shaft-eccentric B is set on the shaft the same as the ordinary eccentric to impart the usual travel to the valve A, and the governor-eccentric D is set so that its greatest travel will be the same in time and throw as that of the shafteccentric-B. When the engine is starting,

the two eccentrics travel together and a full stroke is given to the valveA, as the pins H and H of the yoke H are held parallel to the center line of the engine and move in the arc of a circle governed by the rocker-arm F. The lever J receives its motion from the pin H acting through arm L and pin K on the said lever, which, by being connected with the yoke H by means of link I and pin H causes the said pin K to approximate the arc of a circle due to the action of the radius rocker-arm P on thearm L. Vhen the engine is running, the governor shortens the stroke of its eccentric D, and the latter consequently gets ahead of the shaft-eccentric 'B, thereby causing the pin E to move ahead of pin H so that a swinging motion is given to the yoke H and a like motion to the lever J by the action of the link I, connecting the pins H and J with each other. The motion thus given to the lever J causes the pin J to move up and down as well as horizontally, so that the stroke of the valve is shortened accordingly. The shaft or pin 0 on the radius rocker-arm P acts as a fulcrum for the lever J by means of the triangularly-shaped arm L, causing the said pin J to travel in a path similar to the figure 00. The result of the vertical movement of the pin J 4 and the consequent movement given to the linkNand valve A is thus caused by the action of the governor-eccentric D and the shaft-eccentric B to produce a variable automatic cut-off and constant closing and opening of the exhaust at the proper time, that is, according to the speed of the engine.

'It is understood that the downward movement of the pin J after the cut-off causes the rate of travel of the valveAto be reduced between the cut-off and exhaust-closing to give a constant compression of about five volumes in a two-per-cent. clearance at all points of the cut-off, say from about one twenty-fifth to seven-tenths of the stroke.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. In a valve-gear, a lever extending in general direction the same as the valve-stein and operating said valve-stem, an eccentric of V fixed and one of variable throw connected to a vertical vibration to the said lever, substantially as shown and described.

2. A valve-gear comprising a rocker-arm connected with the governor-eccentric, a yoke carried by the said rocker-arm and having connection with the shaft-eccentric, and a lever having a link suspension from said yoke and from a fixed point, connected with the slide valve and also with the said yoke through the medium of an interposed lever, and said interposed lever, substantially as shown and described.

3; A valve-gear comprising a rocker-arm controlled from the governor-eccentric, a yoke hung on the said rocker-arm and controlled from the shaft-eccentric, an arm hung on the said yoke, a lever fulcrumed in the said yoke and controlling the slide-valve, and a link connecting the said lever with the yoke, substantially as shown and described.

4. A valve-gear comprising a rocker-arm controlled from the governor-eccentric, a yoke hung on the said rocker-arm and controlled from the shaft-eccentric, an arm hung on the said yoke, a lever fulcrumed in the said yoke and controlling the slide-valve, a link connecting the said lever with the yoke, and a second rocker'arm having a pin engaging the said arm, substantially as shown and described.

- 5. Avalve-gear comprising a rock-arm connected to the governor-eccentric, ayoke suspended upon the rock-arm having a horizontal lever attached to one end thereof, an eccentric of fixed throw attached to said yoke below its pivot, a lever carried upon link connections from said yoke-lever and in general occupying the same direction as the valvestem, and connected at one end to the valvestem, substantially as described.

FRANKLIN PILKINGTON.

Witnesses D. O. BLACKWELL, E. H. HANNA. 

